JPH0122625Y2 - - Google Patents

Description

[Detailed description of the invention] Technical Field The invention provides at least one guide which is driven to rotate in a plane intersecting the sewing direction and is movable between an operating position and a standby position. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fabric guiding device in a sewing machine, which has a wheel and a carrier associated therewith, on which a transmission means for the guide wheel is arranged.

PRIOR ART Guiding devices of the above type are known, for example, from US Pat.
It has become publicly known from the publication No. 4292908. This known guiding device has upper and lower guiding wheels for guiding a fabric consisting of two layers. The two guide wheels are located on the circumferential side of the wheel body.
It carries freely rotating rollers arranged across the plane of the wheel. Each guide wheel is
It is mounted on a carrier formed as a pivotable arm, on which a belt drive is also arranged, which connects the guide wheel with a motor fixed to the carrier.

Since the guide wheel has a non-circular peripheral side, like a polygon, because the rollers are spaced apart from each other, the carrier moves up and down slightly alternately as the guide wheel rolls over the fabric. exercise. To these movements, vibrations caused by the sewing machine are optionally added, so that the carrier oscillates uncontrollably at constant sewing and operating speeds. These vibrations interfere with the correct operation of the guide device.

Purpose The purpose of the present invention is to provide a guide device that is almost unaffected by vibrations generated by itself and vibrations generated by others.

Structure, operation and effect The guide wheel is supported on a rocking lever of low mass which is subjected to the force of a spring, and the carrier is arranged so that the guide wheel does not move, at least when it is in the operating position. As a result of the procedure, the guide wheel and the rocking lever form a swingable system that is decoupled from the carrier of the guide wheel and the motor, which system ensures that even at high rotational speeds the guide wheel does not touch the fabric. Achieves maintaining uniform frictional contact. In this case, the force exerted by the spring mechanism on the rocker lever, and thus the force pressing the guide wheel against the fabric, is relatively small, so that the forward movement of the fabric is not impeded. Due to the fact that the oscillation of the guide wheel is decoupled from the carrier, the vibrations generated by the sewing machine and transmitted to the carrier are not transmitted at all to the oscillating lever and the guide wheel, or only part of the vibrations are transmitted to the oscillation lever and the guide wheel. Reportedly.

The carrier for the guide wheel arranged above the fabric is formed as a pivotable arm, which arm is moved by means of a pressurized fluid-actuated cylinder towards an abutment defining its working position. And it is locked in this position.

The stopper of the swinging lever described in claim 2 of the utility model registration cooperates with the stopper surface of the arm to determine the lowest point of the swinging lever.

By means of the pressure fluid cylinder according to claim 3 of the utility model registration, the guide wheel is raised high, so that when a new fabric is inserted, there is sufficient space for viewing and manipulating it. It will be done.

When a new fabric is inserted, the guide wheel located below the fabric does not need to be lowered so far as to lift the upper guide wheel, so in this case the carrier is placed in a fixed position. The piston rod of the pressure fluid cylinder used for lowering is simultaneously used as a stop for determining the operating position of the guide wheel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in more detail by means of embodiments shown in the accompanying drawings.

In the accompanying drawings, only a portion of the arm 2 and head 3 of the sewing machine 1 are shown. Arranged in the head 3 is a needle bar 4 which is driven in a known manner and carries a needle 5 for guiding the thread.

The guiding device 6 has an upper guide wheel 8 and a lower guide wheel 9 in order to correctly guide the edges of the two fabric layers separated from each other by an intermediate plate 7. The two guide wheels 8, 9 carry freely rotating rollers 11 arranged on the circumferential side of the wheel body 10 so as to intersect the plane of the wheel body.

The upper guide wheel 8 is supported on a swing lever 12 of low mass and of short design, which swing lever is connected by means of a pin 13 to one arm 1 as a carrier.
It is pivoted to the end of 4. The swing lever 12 has a protrusion 15 that acts as a stopper, and the protrusion 15 is supported by coming into contact with a stopper surface 17 of the arm 14. An adjustment screw 16 is screwed into the stopper 15 and an adjustment screw 16 is screwed into the stopper surface 17 so that the relative position of the swing lever 12 with respect to the arm 14 when the stopper 15 and the stopper surface 17 are in contact can be adjusted. are formed so that they come into contact with each other.

A protrusion 18 is formed on the arm 14, and the protrusion 1
A presser foot adjustment screw 19 is screwed into 8. A compression spring 20 is disposed in the hollow shaft portion of the presser adjustment screw 19, and the compression spring 20 presses the upper surface of the swinging lever 12 and exerts an action of pressing the stopper 15 against the stopper surface 17. Components 18 to 20 are the first
A spring mechanism 21 is formed.

The arm 14 is fixed at its other end to a plate 22 which is pivotably arranged on a support 24 by means of a pin 23. The support 24 is fixed to a table 25, only a portion of which is shown. Board 2
A step motor 26 is disposed at 2, and this motor is connected to a toothed belt 28 via a belt wheel 27.
to drive. The toothed belt 28 is attached to a belt pulley 29 formed on the wheel body 10 of the upper guide wheel 8.
It is coupled with the drive.

A compressed air cylinder 31 is arranged on an angle member 30 fixed to the table 25. A rod 33 fixed to the piston rod 32 cooperates with a projection 34 formed on the plate 22. A compressed air cylinder 36 is arranged on another angle member 35 which is fixed to the table 25. A rod 38 fixed to the piston rod 37 cooperates with a projection 39 formed on the plate 22. Angle material 35
A threaded rod 40 is further arranged as a stopper, and the threaded rod 40 is screwed into the lock nut 4.
1 is adjusted and fixed.

This threaded rod 40 has a protrusion 3 as a stopper surface.
Collaborate with 9. The lower guide wheel 9 is supported on a swinging lever 42 which has a short L-shape and has a low mass.
This swing lever 42 is pivotably arranged on a lower support member 44 as a carrier by means of a pin 43.
This lower support member is fixed to the table 25 by a long hole 45 and two screws 46. A step motor 47 is arranged on the lower support member 44.
This motor drives a toothed belt 49 via a belt pulley 48. The toothed belt 49 runs via a deflection wheel 50 mounted on the rocker lever 42 and a further deflection wheel 51 arranged on the pin 43 and over the wheel body 1 of the lower guide wheel 9.
It is drivingly connected to a belt pulley 52 which is formed at 0.

A threaded rod 54 is attached to the protrusion 53 of the lower support member 44.
is fixed. A compression spring 5 is mounted on the threaded rod 54.
5 is inserted, and this spring has one end attached to the adjustment nut 5.
6 and the other end thereof is supported by a protrusion 57 formed on the swing lever 42. Projection 57
has a hole (not shown) for passing the threaded rod 54 therethrough. Components 53 to 57 form a second spring mechanism 58 .

A compressed air cylinder 59 is attached to the lower support member 44.
is fixed and adjustable in position. The piston rod 60 cooperates with a projection 61 formed on the swing lever 42.

In the operating position of the upper guide wheel 8, the piston rod 37 of the compressed air cylinder 36 is pulled back and the piston rod 32 of the compressed air cylinder 31 as a pushing means is pushed out, so that the arm 14 can be moved via the projection 39 onto the threaded rod. Supported by 40. The position of the threaded rod 40 serving as a stop defines the downward pivoting position of the arm 14 and thereby the downward position of the upper guide wheel 8. The screw 16 defining the downward pivoting position of the rocking lever 12 is adjusted in such a way that the guide wheel 8 slightly contacts the exposed intermediate plate 7 . If there is a fabric layer on the intermediate plate 7, the rocking lever 12 will be pivoted clockwise against the force of the compression spring 20 by a small angular amount. In this way, the guide wheel 8 and the rocking lever 12 are able to move relative to the arm 14 when oscillations or vibrations occur.

In the operating position of the lower guide wheel 9, the piston rod 60 of the compressed air cylinder 59 is pulled back. The vertical position of the compressed air cylinder 59 is such that the compression spring 55 is aligned with the protrusion 6 of the swing lever 42.
1 onto the piston rod 60 and in such a way that the guide wheel 9 lightly contacts the exposed intermediate plate 7. If there is a fabric layer under the intermediate plate 7, the rocking lever 42 will be pivoted clockwise by a small angular amount against the force of the compression spring 55.
In this way, the guide wheel 9 and the rocking lever 42 can move relative to the arm 44 when an agitation or vibration occurs.

In order to insert the fabric layer above and below the intermediate plate 7, the piston rod 3 of the compressed air cylinder 31
2 is pulled back and the piston rods 37 and 60 of the compressed air cylinders 36 and 59 are pushed out, thereby causing the swinging lever 12 and the arm 14 to be pushed out.
The swing lever 42 is then pivoted clockwise, so that the guide wheels 8, 9 are moved away from the intermediate plate 7.

[Brief explanation of drawings]

The attached drawing shows one embodiment of the guiding device of the present invention. 8, 9... Guide wheel, 12, 42... Swing lever, 14... Arm (carrier), 15... Stopper,
17... Stopper surface, 21, 58... Spring mechanism,
31, 36... Compressed air cylinder, 40... Threaded rod (stopper), 44... Lower support member (carrier), 59... Compressed air cylinder, 60... Piston rod.

Claims (1)

[Claims for Utility Model Registration] (1) At least one guide wheel driven to rotate in a plane intersecting the sewing direction and movable between an operating position and a standby position; A fabric guiding device for sewing machines, which has a carrier associated therewith, in which a transmission means for a guide wheel is arranged, said carrier being formed from a pivotable arm 14; A stopper 40 for determining the operating position of the arm and a pressing means 31 for pressing the arm against the stopper 40 are attached to the arm, and the supporting body supports a guide wheel 8 with a small mass. A guide device for a sewing machine, characterized in that it has a swing lever 12, and the swing lever is connected to a spring mechanism 21 that presses a guide wheel 8 against the fabric. (2) The guide device according to claim 1, wherein the swing lever 12 has a stopper 15 supported by the stopper surface 17 of the arm 14. (3) The guide device according to claim 1 or 2, wherein the arm 14 is provided with a pressure fluid cylinder 36 for lifting it.